In the base stations of a mobile telecommunications system that is centrally managed from a network management system there are a number of functions realised by software and hardware resources that support the activities of the base stations. These resources are usually devised to detect faults in input signals or in operation results. Fault signals are generated in the resources and are transmitted to a software based fault manager in the base station.
The increasingly complex nature of modern base stations entails that there are many sources for generation of fault signals, and there are also many instances where a single fault may give rise to a large number of consequential or side effect fault signals. An important task for the fault manager is therefore to analyse which faults to prioritize and to determine dependent on correlation and filtering of the fault signals if an alarm signal shall be generated and conveyed to the central network management system.
Model based fault analysis techniques are commonly used in fault managers to identify faults that shall be reported to the central network managements system. This requires definitions of all resources and any related faults that may occur as well as any correlations between the resources and rules for how to report an identified fault to the network management system. Commonly the fault manager receives faults in a resource perspective and is devised to transmit alarms to the network management system in a model perspective. Each fault analysis model depicts only one defined system, and a new model must be created each time the system is modified or the definition of the system is updated.
This is a problem for the manufacturers as well as for system operators since there is a constant need to add new features and resources to the telecommunication system. The fault analysis models are commonly hard-coded in the fault manager software. The introduction of new features and resources require a new or a modified model, and with the common technology this also requires the development and installation of new fault management software. This, in its turn, entails high costs for code development, verification and maintenance as well as an outage of the base station during the installation time. An alternative is to have the fault analysis algorithm implemented in the resource, which entails that the fault analysis algorithm is implemented in several instances, i.e. one instance of a fault analysis algorithm in each resource which again is ineffective in cost and maintenance.
There is therefore a need for a more flexible fault management software that enables a smother modification or updating of the fault analysis model.